1. Field of the Invention
The present invention relates generally to cable modem networks and provisioning cable modems. More specifically, it relates to enabling a cable modem to have multiple qualities of service or ISPs without altering any configuration data at the cable modem network headend.
2. Discussion of Related Art
As cable modems proliferate, situations will arise in which a single cable modem must accommodate various ISPs or various levels of quality of service (QOS) from a single ISP. A household may have one cable modem connected to one or more PCs or other IP-addressable devices. Members in the household will have various needs in terms of QOS, speed and other factors. For example, one member of the house may need a high QOS because he is telecommuting and his employer is paying for the comparatively high-priced service. A child in the house may not need fast or the highest-QOS Internet access but rather only modest Internet access. Yet other members of the household can get along with mid-tier QOS Internet access (but will eventually want to upgrade to a better service). The telecommuter may be required to use ISP “A” because his employer requires it if they are going to pay for it and the other members of the household may use ISP “B” which is the commonly used ISP in their geographic area. Alternatively, all members of the household can use one ISP (such as ISP “A”) and have different QOSs or the household can have three different ISPs. In any case, a single cable modem has to enable multiple QOSs and ISPs if necessary. It can be noted that the cable modem network is deemed an open resource and thus has an open access requirement. This allows competition among the ISPs which want to provide Internet access service for cable modem users.
Presently, in order for a cable modem to handle the above scenario, changes must be made to the cable modem network operator's provisioning system, i.e., the DHCP/TFTP server, and to the cable modem network headend, also referred to as the CMTS. The CMTS must be modified such that for each new QOS or ISP associated with a cable modem, a new virtual cable interface is created. That is, a new sub-interface under a primary cable interface needs to be created wherein, a primary cable interface is implemented with one line card in the CMTS. For example, cable modems A1 through A5 using ISP “A” which services a certain range or group of IP addresses gets its own virtual or sub cable interface. Creating and managing all of the sub-interfaces, which are likely grow, at the CMTS require more work by the network operator and are error-prone operations potentially disrupting service for many customers.
Associated with each data packet coming upstream from the cable modem to the CMTS is an MPLS (multiprotocol label switch) label or tag. As is known in the field of cable modem networks, the MPLS tag is used as an MPLS-VPN (virtual private network) tag as is common when a shared link is used to send traffic. Presently, with the DOCSIS 1.0 design, the SID of the data packet is used to determine which MPLS/VPN tag is given to the data packet. Data traffic is labeled with an MPLS/VPN tag based on external criteria or policies. The traffic is then treated differently based on the MPLS/VPN tags. For example, in the cable modem network scenario, a data packet is sent upstream to the CMTS and then typically forwarded to another network, such as the Internet, via an edge router, for example. In the example above, each ISP can be assigned a unique MPLS-VPN tag that identifies traffic belong to that ISP. The MPLS-VPN tag can then be used as a basis to apply security/QoS or any other defined policies on the traffic.
Therefore, it would be desirable to enable a cable modem network to accommodate the addition of ISPs or QOS levels to a single cable modem by only having to update the provisioning system and without having to modify the CMTS. It would also be desirable to have a more efficient way to map a data packet to a MPLS/VPN tag in the CMTS. In the process, IP address management would be simplified by not having to create multiple sub-interfaces in the CMTS.